Television apparatus



Feb. 17, 1931. P. R. EGGER 1,792,683

TELEVISION APPARATUS Filed March 22, 1930 2 Sheets-Sheet 1 1 I E] 7 I W-INVENTOR.

Feb. 17, 1931. p. R. E GGER 1,792,683

TELEVISION APPARATUS Filed March 22, 1930 2 Sheets-Swat 2 5 6. To provide improved ineansfor Patented Feb. 17, 19 3 1 PATENT, OFFICE i a rant 1;.) EGGER, or DAVENPORT, Iowa I TELEVISION ArrAnA'rus 7 appli'cation filedMarch 22, 1930. Serial No. 438,004. 1 a

My invention relates to'i-mprovementsin I television apparatus.

The objects: of my invention are: i 1. To provide improved means in transomitting sets for scanning the object to be transmitted'televisionally and to provide-improved means in receiving setsfor-receiving and transmitting to the screen the beams of light from the glow-lamp 10 2. To provide means in transmitting sets bywhichthe object to .betransmitted may" be scanned in continuous bands instead of by separate and distinct dots of light and to provide means in receiving sets by which the light received maybe cast upon the screen in a series of successive bands-rather than in a series of separate: and. distinct points of light;" 1 V i 3. To provide means by which the apparent black lines'between the apparent lines of illumination on a screen of a receiving set, may be reduced or eliminated and, also to provide means by which the apparent white lines between the illuminated lines on such a screen due to overlapping of paths of light or illuminated bands, may be reduced or elim inated;

4. To provide a simplified, improved multiple mirror for television sets; v

5. To provide means by which objects may be transmitted televisionallyeither by direct light reflected from the object orbycasting an image of theobject upon a'screen and transmitting such image;

chronizing televisionapparatus. i

I attain these objects by the means illustrated in the accompanying drawings, in which, I

Figure 1 is a plan view' of a television camera embodying my invention, but. with the top or cover plate removed; 1

Figure 2 is a side elevation of the same with the side plate of the housingiremoved to expose the interior; V

Figure 8 is a rear elevation of my apparatus with the rear housing plate removed to disclose the interior;

Figure 4 is a greatly enlarged detail of my multiple "mirror 5 1 V Figure 5 is an enlarged cross-sectional Edetail on the line 5-5 of Figure 4; a

Figure 6' is a view of the slotted slide which is removably mounted upon oneof the lenses;

. Figure 7 is a diagrammatic view of a receiving set;

Figure 8 is a diagrammatic-view of a transmitting set but with the space-between the object, 15, and the -screen,6, foreshortened. In transmitting, my reflector may be used in the combination shown in Figure 8 'or if desired, thescreen, 6, and the lenses, 4: and 5, may be omitted, the object may be properly illuminated and the light may bereflected directly from: the obiect to the. mirrors, :3. When so used, it will be advisable to enlarge the reflecting element, '3, to a considerable extent. 1

Similar numerals refer to similar parts throughout the several views.

I have not attempted to show the apparatus for transmitting -the;light waves after they have been thrown upon the photo-electric cell of the transmitter nor the apparatus for re.- ceiving'the electric waves from the air, wire or other medium by which they are transmitted and bringing'them to the neon or glow-lampsbefore being amplified to be cast upon the screen. Such apparatus is well known and in common use and my special devices may be applied to and used with any desired form thereof.

My apparatus comprises a box-like housing, 11, of wood or any other suitable mate rial. For convenience I refer to the right.

end of Figure 1 as the front andto the left end of it, as the rear; also to the top of Figure 1, as the left side of the camera or housing and the bottom of Figure 1 as the right side of the camera or housing, 7

. The housing, 11, has a horizontal partition, 12, secured transversely therein and extending from the front nearly to the rear of 'the housing. A vertical, light-proof partition, 13, is mounted in the camera and extends from the front,"back nearly to the rearof the partition, 12, where it is joined by transverse partitions, 14: and 14;. A screen, 6, is mounted between th par it o 13, and the right side wall of the camera. In the front plate of the houslng I mount a lens, 7, adapted to focus upon the screen, 6, and image of ob- ]ects comlng within the field of the lens, 7.

In the partltion, 14, I mount a piano-conr L cave lens, 0, adapted to transnut the llghb rays from the screen- 6- 1n )arallel lines to the 7 7 plano-convex lens, 4:, which 1n turn transmits them to the revolving reflecting element, 3. This refiectmg element, 3, comprises a shaft of Monel metal or other metal adapted to take a mirror-like finish and has a plurality of mirrors, 3, cut transversely of the shaft through the center line thereof. Each mirror comprises a flat surface as long as the diameter of the shaft and the body of the shaft is cut away very much like a twist drill. The successive inirrers are cut with an axial angular variation sufficientto permit the beam of light transmitted by one mirror to clear the photo-electric c-ell before the beam of light from the next succeeding mirror strikes the photoelectric cell. I prefer an angular variation of approximately two and a half degrees. The face of each mirror, 3,- is plane. I

The reflecting element, 3, has its upper end mounted in any suitable form of bearing, 16, united to the top of the housing, 11, and its lower end is preferably united by a chuck, 17, to the shaft of a motor, 18, mounted within the housing or box, 11.

Upon the bottom of the box, 11, I mount a bearing plate, 25, carrying a plurality of heavily grooved rollers, 23,- by studs, 24, or

other suitable means. The motor, 18, is mounted within a cylindrical sleeve, 20, and the lower end of the sleeve, 20, is provided with an inwardly extending flange or track, 21a, which extends into the grooves of the rollers, 23, and supports thereon the sleeve, 20, and the motor, 18, which is adjustably secured within the sleeve by the set screws, 19.

Around the base of the sleeve, 20, I provide a spur gear, 21, which meshes with a drive gear, 22, mounted upon the shaft, 26; The shaft, 26, has its lower end rotatably mounted in a bearing block, 27 secured to the bottom of the camera and its upper end extends through the top of the camera and is provided with a knob, 28, by which it may be turned. It will be seen that the turning of the knob, 28, will turn the sleeve, 20, which will carry with it the motor, 18, and in this ,3 way the reflecting element, 13, may be ad'- vanced or retarded.

When used as a transmitting set, the mirrors, 8, will reflect successive bands of the image appearing upon the screen, 6', and transmit them through the lens, 2,- to the photo-electric or light-sensitive cell, 1, and as the light transmitted by the mirrors, 3', varies in intensity, the light reflected to the cell, 1, will vary and the electric current set up within the cell will also vary; The varying current is then led from the cell, 1, by suitable wiring, to the amplifying and trans mitting apparatus.

When used as a receiving apparatus, a neon or glow-lamp, 1a, is substituted for the cell, 1. The receiving current after being amplified and led to the glow=lamp, la, develops a varying light therein and the beams of light from the lamp, 1a, are transmitted through the lens, 2, to the reflecting element, 3, and thence reflected by the mirrors, 3, through the lenses, 4 and 5, to the screen, 6, where they become visible to the eye.

The screen, 8, with the slot, 8a, therein, is removed from the lens, 2, when the apparatus is used for receiving and the lens, 2, fo'ciises the light from the glow-lamp, 1a, in a vertical line upon the reflecting element, 3;

The back or uncut portion of the reflecting element, 3, may be ainted a dead black or otherwise darkened o prevent the reflection of light therefrom.

The photo el'e'ctric cell, 1, or glow-lamp, 1a, may be mounted in a socket, 9, upon a suitable support, 10, secured Within the box, 11, in

any desired manner and with terminals, 10, to which the wiring system may be connected, The lens, 2, is secured in a suitable mount ing, 2, secured to the partition, 12, by set screws, 2, or other suitable means p In the operation of my device the object, 15, properly illuminated, is placed in front of the lens, 7, and an image of the object fd-- cus'ed upon the screen 6.-

The rays of light from the screen, 6, are then transmitted through the lenses, 5 and 4, to the scanning? element, 8. The scanning element is mounted with its axis parallel to the vertical axis of the screen, 6; The length of the scanning: portion of the scanning ele= ment, 3', is sufficient to cover all the parallel rays of light transmitted from the screen, 6; The rays of light reaching the first or upper mirror upon the scanning element, are reflect= ed to the photoelectric cell, 1, but as they must pass through the slot, 8a,- in order to reach the cell, 1, they reach the cell iii narrow pencils of light rather than in a broad band, which pencils, however, are continuous and not separated by intervening dark spots. As the mirror revolves with the shaft, it catches the light rays preferably from one side of the screen first, and follows this by catching the successive rays coming from a band across the screen and transmitting them to the photo-electric cell.

In case no screen is used, a combination of lenses will be necessary which will reduce the area of the parallel rays coming to the scanning element to equal the length of the body thereof or if desired, a large scanning element can be used equal in length to the length of the object to be transmitted and as the various mirrors revolve in parallel planes, they will successively and respeetive'lytrahsniit to the cell, 1, only the portion of the object which lies in the various planes. Of course this would require a correspondingly large photo-electric cell, but large cells have been made large enough to receive many subjects in this way, or if desired, the mirrors of the scanning element may be inclined sulficiently, longitudinally of the shaft, to condense the rays somewhat at the photo-electric cell. i

As no two mirrors would at any time be in a position to transmit rays from the object, 15, to the photo-electric cell, 1, at the same time, no interference could be caused by this arrangement.

My apparatus is primarily designedfor the system of television utilizing successive transmission of circumscribed areas of a fully illuminated object, but it is equally adapted for use in those systems whichilluminate the subject by illuminating successive circumscribed areas progressively and when so utilized, an arc-lamp or other intense source of light would be substituted in place of the cell, 1, in Figure 8, the lenses, 4, 5 and 7, andthe screen, 6,'eliminated and pencils of light will be reflected by the scanning element, 3, across the face of the subject in successive bands at a speed suhicient to cover the entire subject fifteen times per second or thereabouts.

It is obvious that the mirrors, 3' in my scanning element may be arranged in a single spiral as shown in Figure 4 or they can be arranged in a plurality of spirals to avoid the efiort of the eye to follow the light beams upon the screen, it being necessary only to arrange the mirrors so'that no two of them will be transmitting light rays to the same photo-electric cell at the same time. Of course a plurality of spirals may be arranged with a corresponding plurality of photo-electric cells if desired, and I do not limit my claims to the precise arrangement of mirrors illustrated in the drawings.

My apparatus may be so arranged as to sweep or scan either the viewing screen or the image upon the focusing screen or the object itself either vertically or horizontally, but I prefer to arrange it in such a way that the scanning will begin with the upper lefthand corner and extend in successive horizontal bands across and down to the lower righthand corner.

The number of'mirrors may be varied to suit the requirements of any particular case.

With an angular variation of two and onehalf degrees, one hundred and forty-four mirrors might be formed in a single complete spiral, thus making possible the use of a large number of mirrors and correspondingly increasing the definition of the reproduction upon the viewing screen. The unit areas to be thus scanned would be comparatively small and the sharpness of definition would thereby be increased. I do not limit my allel to and in line with the axis of the shaft.

2. In a television set, a scanning element comprising a revolvable shaft, and 'a plurality of narrow mirrors united thereto extending transversely of the shaft and having the successive mirrors arranged about the shaft in progressively increasing angular relation to the first mirror, the axis of he shaft passing through the surface of each mirror.

3. In a television set, a scanning element comprising a revolvable shaft, and a plurality of narrow plane mirrors united thereto extending transversely of the shaft, said mirrors having their short diameters parallel to and in line with the axis of the shaft and their long diameters at right angles thereto.

4:. In a television set, a scanning element comprising'a revolvable spiral shaft, and a plurality of progressively arranged narrow mirrors united thereto extending transversely of the shaft and having the axis of the shaft passing through the surface of each mirror. 7

5. In a television set, a scanning element comprising a revolvable shaft having onehalf of the body thereof cut away on the axial line thereof to form a broad stepped-spiral face, and a plurality of narrow mirrors formed integral therewith extending transversely of the shaft upon the face of the spiral.

In testimony whereof he aflixes his signature.

PAUL R. EGGER. 

